First, use -XX:MaxPermSize instead of -XX:PermSize. If this JAVA_OPTS is from your server (not from jmeter JAVA_OPTS shell variable), it'll affect the performance of your server, but it could be for good or for bad. If your box have much more than 6GB, say 10GB or more, and you're using a 64-bit JVM, it'll affect for good. If is less than this, it'll be in trouble.
Remember that SO, the most of them, needs at least 1GB to work and that free memory to allow it creating new thread hooks (1GB is much more than it'll need). With these points in mind you'll need at least 2GB of free memory. So, 10GB (6GB to JVM + 4GB to SO) will be very good in your case. Other points have to be considered when testing the performance of your server. JVM GC configuration tuning, Server specific configuration tuning, application bottlenecks, etc. Try to use a profiler, like Visual VM, to monitor server and JVM behavior when load testing them. Try to change one configuration at a time and take note of the performance changes. This way you'll know what configurations are the best to your case. Hope it helps you. Flávio Cysne 2012/4/11 Nisha G. <[email protected]> > Hello All, > > I am seeking a suggestion on one scenario... > When I performed my tests with JMeter on Performance Server (having > JAVA_OPTS=%JAVA_OPTS% -Xmx2048m -XX: PermSize=1024m) and after several > attempts we concluded that our Product(Developed on Java platform) donot > support more than 150 Active Users doing different transactions with > different login credentials. > > Query: If I update the JVM settings from 2GB to 4GB or more (i.e. > %JAVA_OPTS% -Xmx4096m -XX: PermSize=2048m). Will it affect the above > performance numbers. (Will it be able to support more i.e. 150+ number of > concurrent active users on server) ? > > Please prove me wrong as I think it will not affect the performance. > > Thanks, > Nisha >
